Other than LibreOffice/OpenOffice.org Impress what good presentation making tools are available for Ubuntu? I prefer a GUI tool which can export to PDF as I have to make presentation in Windows PC. Can PDF support animations with Adobe Reader 8/9?

I remember reading HTML presentations are often attractive but don't know how to create one. Are there nice tools for that purpose? Can such a presentation run with all effects on an older browser, say IE6/7?